***This is your notification that it is VERY likely that some of these loads, if you manage to fit them in a normal 357 magnum chambered firearm, will absolutely blow up your gun and injure you. They were developed in, and should only ever be used in, firearms with actions known to be strong enough to handle high pressure rifle cartridges. Please do not try these in your K-frame and become fodder for anti-gun propaganda on the Huffington Post spam feed. If you have questions about "357+P" loads, please ask!***
One of my grand plans for the past few years has been to shoot heavy subsonic projectiles out of an Encore with a suppressor. So far I'm not doing too badly: Encore? Check. Threaded barrel? Check. Heavy boolit mold? Check, an Accurate 35-245P. I am currently waiting for my suppressor to be approved, so in the meantime I'm exploring what other potential this mold has. Turns out it's quite a lot, with the right powder.
Since my previous testing with duplex loads had been conducted with my Henry H015 and I just got a scope put on it, I figured I'd keep going with it - I think it's more representative of what folks might see out of the lever guns in 357 mag that are so popular. For this testing the Accurate 35-245P was cast out of a relatively hard scrap alloy, sized to .358", powdercoated, and sized to .358 again. Here are my first round of results. Please forgive my customary "bad / OK / Good" accuracy rating, without a shooting bench I am not in a situation to shoot for groups that would be meaningful outside my own backyard.
Gun: Henry H015 Single Shot, 357 Magnum
Brass: Hornady
Primer: CCI Small Magnum Rifle
OAL: 1.690"
Boolit (PC'd) Green Dot (gr) Lil'Gun (gr) FPS Accuracy Notes Accurate 35-245P 5.5 0.0 1070 ???? Accurate 35-245P 5.7 0.0 1081 Good I will probably use this as a standard subsonic load. Accurate 35-245P 6.0 0.0 1112 ???? Accurate 35-245P 6.5 0.0 1148 ???? Possibly a bit stiffer extraction, probably a good max load. Accurate 35-245P 7.0 0.0 1196 ???? Slightly stiff extraction Accurate 35-245P 0.0 8.5 1197 ???? Accurate 35-245P 0.0 9.0 1264 ???? Accurate 35-245P 0.0 9.5 1316 ???? Accurate 35-245P 0.0 10.0 1334 ???? Accurate 35-245P 0.0 10.5 1372 ???? Accurate 35-245P 0.0 11.0 1416 ???? Accurate 35-245P 0.0 11.5 1473 Good This produced the only ragged hole group I've ever gotten with this gun. Accurate 35-245P 0.0 12.0 1483 ???? Mild deformation around firing pin strike. MAX LOAD. Accurate 35-245P 0.0 12.5 1563 ???? Deformation around firing pin strike, harder to break action. DO NOT USE.
Call me pessimistic, but I wasn't expecting to knock on the door to 1500fps with this boolit before I became uncomfortable with proceeding further. My alloy was dropping from the mold at about 237gr, so that puts the muzzle energy for the 11.5gr Lil'Gun load at 1147ft*lbs. I would wager that performance will cover many of the needs of deer hunters in the mountains of the eastern USA. Comparing to the figures measured by Ballistics By the Inch, it's slightly more oomph than a 240gr 44 Mag out of a 12" revolver barrel but with a better drag coefficient.
My Encore has a fast-shooting 12" barrel, so I'm looking forward to working some of these up for it. Will come back with more when I've got it!
EDIT:
Threw together some test loads yesterday with the Encore. Performance was better than expected. Never got sticky extraction or anything, but did get uncomfortable going higher. There is nothing that lives in the eastern USA that I wouldn't be comfortable using some of these loads to hunt at ranges which are practical with a red dot on a handgun.
Gun: T/C Encore, 12" MGM barrel, 357 Magnum
Brass: Hornady
Primer: CCI Small Magnum Rifle
OAL: 1.690"
Boolit (PC'd) Green Dot (gr) Lil'Gun (gr) FPS Accuracy Notes Accurate 35-245P 0.0 7.8 1080 Good Accurate 35-245P 0.0 8.0 1122 ???? Accurate 35-245P 0.0 8.5 1173 ???? Accurate 35-245P 0.0 10.1 1340 ???? This charge recommended by Badman Bullets to achieve subsonic velocity with their 230gr WC Accurate 35-245P 0.0 10.5 1321 ???? Accurate 35-245P 0.0 11.0 1359 ???? Accurate 35-245P 0.0 11.5 1393 ???? Accurate 35-245P 0.0 12.0 1414 ???? Accurate 35-245P 0.0 12.5 1448 ???? Accurate 35-245P 0.0 13.0 1480 ???? Lightly compressed Accurate 35-245P 0.0 13.5 1562 ???? Compressed. Slightly-flatter primer, change in dynamic V/C. MAX LOAD.